Android :: How To Hide Application Icon From Desktop?

I defined an application which is only used from my other application. So I would like to hide the icon of this application, so that the user can't see it on the desktop of his phone (or how do you call the thing where all apps are listed?). My manifest file looks the following way:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="xyz.games.pacman.controller" android:versionCode="1" android:versionName="1.0">
<uses-permission android:name="android.permission.BLUETOOTH"/>
<application android:icon="@drawable/icon" android:label="@string/app_name">
<activity android:name=".PacmanGame" android:label="@string/app_name" android:screenOrientation="portrait"> <intent-filter>
<action android:name="pacman.intent.action.Launch" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter> </activity>
<receiver android:name="xyz.games.pacman.network.MessageListener">
<intent-filter> <action android:name="xyz.games.pacman.controller.BROADCAST" />
</intent-filter> </receiver> </application> <uses-sdk android:minSdkVersion="7" /> </manifest>

I already read this question:
http://stackoverflow.com/questions/1063604/how-to-hide-an-application-icon-in-android-emulator
But if I just remove the line
<category android:name="android.intent.category.DEFAULT" />
in my manifest, the activity isn't working at all (ActivityNotFoundException in the calling activity). I already tried android.intent.category.EMBEDDED but this doesn't work too. In the Internet I found CommonsWare answer http://osdir.com/ml/Android-Developers/2010-06/msg03617.html that it can be done using PackageManager. Unfortunately, it isn't explained how exactly and I couldn't find a solution by browsing the PackageManager API.